This invention is related to advanced timpani, or kettledrum in another word, which are equipped with quick and accurate tuning system. It is also related muffling apparatus for timpani. And it is further related to new feature of tuning and muffling programming.
Timpano, singular form of “timpani” which is plural form, produces sound with clear pitch. A circular membrane called head covers a big kettle-like body. Rim of head is pressed to body by a hoop. In old time, six or eight hand screws around the hoop moved relative position of hoop to body, and then changed tension of the membrane. Player changed the pitch by adjusting the tension of membrane. It took time to adjust all six screws precisely for head to produce sound of required pitch tone. Until around year 1800, music composer had to compose under constraint of this matter when using timpani. It was common not to change the tone of timpani within one movement.
Then, improved timpani were invented, with which player could change pitch of timpani by rotating one clank handle. In other several inventions, pitch can be changed by angle of foot pedal. These motion links to up-down motion of a center shaft, and then the shaft links to six or eight points of the hoop. So, player could change the pitch with one point operation. It shortened the time required to change the pitch. But proficient player, who could adjust pitch with only foot pedal without listening the sound, was rare. Until today many players have operated pedal and listened to the sound, then corrected the pedal angle. With one or a few cycle of correcting operation, timpani is tuned to correct pitch. Player cannot make loud sound for adjusting the pitch; he must do it with very soft sound not audible to audience. Also, it takes 5 to 30 second depends on player's ability and surround sounds to adjust one timpano. According to these improvement, composers gradually composed music, in which timpani were changed tone in the course of music. But it is not so quick enough that they often use three or four timpani. Also, composers take care to give players enough no-play time for changing pitch of timpani.
Next improvement applied to timpani was attaching a tuning gage to each timpano. In one invention, up-down displacement of hoop was transformed to rotational angle of pointer. In other inventions, foot pedal angle or displacement of some mechanical point of link between foot pedal and hoop is transformed to rotational angle of pointer. In both mechanisms, there is a semi cylindrical bar aside of the pointer, and several sliding markers on the bar, which have characters of tone on them. Player can adjust head tension by observing that pointer comes to marker of desired tone. Positions of markers are precisely set before playing of the day. With these tuning gage, trained players can change tone within say two seconds.
If head is made of natural skin, its tension changes by humidity or temperature. So, even foot pedal or hoop displacement and pointer position do not change, pitch may vary per hour. Plastic head does not receive much effect from humidity. But, body of timpani or various parts of mechanisms may inflate with rise of temperature. As a result, it happens that pitch is shifted even pointer of tuning gage stays at the marker. Actually, top class players do not count on tuning gages. Instead, they adjust with their ears.
Nowadays, electronic tuning meters are available to musicians. They show the pitch of tone generated by every instrument including timpani. Furthermore, a few inventions (U.S. Pat. No. 4,741,242 and others) were accomplished for tuning meter dedicated to timpani. With these meters, not sounds of other instruments but only head vibration was picked up. They display nearest tone name and how much higher or lower the vibration is than the precise pitch. These means resolved the problem, which tuning gages had. And player without sharp ear is able to tune precisely. But, time necessary to adjust pitch does not decrease to less than five seconds, with these tuners or tuning meters. Because player has to produce sound by hitting the head and still need operation of feedback cycles.
With recent invention (U.S. Pat. No. 4,023,462), a motor drives the center shaft up and down, which pulls the head. This motor is driven according to difference between reference period of specified tone and measured period from vibration of head. The motor is driven until said period difference becomes to zero. Thus these form closed feedback loop, and automatic adjustment of pitch is realized. Time necessary to change tone may be in two second including time for pushing bottom to specify the tone and hitting the head.
Summarizing former technology described above; the tuning gage made quick tuning possible, but had problem of accuracy because of variation per hour. Precise tuning technology still asked hitting head. Anyway, it is not possible to change tone consecutively in say 0.2 second, as played with string instrument or trombone.
Four timpani are common in modern orchestra. Composers had to think this constraint. In case they still needed more tones in short time, additional timpani had to be prepared around player. Or they had to ask plural players to play on each set of timpani.
Player has to challenge muffling timpani, which is not well known. Player touches the head to cut off the tone. This action is called muffling. Correct muffling by hands is difficult technique itself Also, muffling is necessary to prevent sympathetic resonance of timpani, which are not hit. Especially, if there are three or more timpani arranged, it is difficult to muffle all the timpani with two hands. In invention U.S. Pat. No. 3,951,032, padded damping plates driven by electromagnetic device are touched heads according to foot switch operation. One foot switch can control all the timpani. But, to prevent sympathetic resonance, it is better to keep padded damping plates in touch status for timpani not use a little while. Until today to resolve this difficulty, just putting felt pads or something like on the heads of unused timpani is commonly used practice. But, in modern or contemporary works, selection of timpani to play on moves frequently, and then to move or take off the muffling felt pads are too cumbersome tasks.